The present invention relates to a vehicle door latch device, and particularly to a vehicle door latch device that prevents a door from opening if a door panel is deformed by a crash.
When a door panel is deformed by a crash, a conventional vehicle door latch device for preventing a door from opening is described in JP2016-505098A.
The vehicle door latch device in JP2016-505098A comprises a rotary catch that can engage with a striker; a pawl that can engage with the rotary catch; an opening lever for releasing the pawl; a rotatable inertial lever; a preventing lever that is rotatably supported to the inertial lever; and a safety lever that is contacted with a contour portion of the inertial lever by a force to apply resistance against a rotation of the inertial lever. When a door handle is operated manually, the preventing lever rotates together with the inertial lever around an axis of the inertial lever. When the opening lever rotates at an excessive high speed owing to a crash, the present lever rotates to a position where it can contact the safety lever, thereby preventing the ratchet from rotating and preventing the door from opening.
However, in the vehicle door latch device in JP2016-505098A, the safety lever is contacted with the contour portion of the inertial lever by a force to apply resistance against the rotation of the inertial lever. Thus, dust adhered into a gap between the contour portion of the inertial lever and the safety lever and a freeze of rain water cause excessive resistance that acts on the inertial lever. Even if the door handle is operated manually, the preventing lever rotates to a position for preventing the inertial lever from rotating thereby causing a problem that the door cannot be opened.